Display backlight is off at startup

[RDA]

Hello.
I installed MX on my laptop Lenovo S540 (Ryzen 5 3550h, Vega 8, 16Gb Ram). There is a problem at startup. When it starts (or reboots) the display backlight remains off until I log in to the system. I am able to adjust the level of the backlight after logging in only.
Does anyone have a solution?

[JayM]

Please run Quick System Info and post your system information whenever asking for help as per the forum rules (which please read.) Just run it then right-click paste in a reply, don't copy/paste. Instructions are here if you need them. Thanks.

[RDA]

Code: Select all

System:
  Host: <filter> Kernel: 5.10.0-5mx-amd64 x86_64 bits: 64 compiler: N/A 
  parameters: BOOT_IMAGE=/boot/vmlinuz-5.10.0-5mx-amd64 
  root=UUID=<filter> ro quiet splash 
  Desktop: KDE Plasma 5.14.5 wm: kwin_x11 dm: SDDM 
  Distro: MX-19.4_kde_x64 patito feo March 31  2021 
  base: Debian GNU/Linux 10 (buster) 
Machine:
  Type: Laptop System: LENOVO product: 81XC v: Lenovo IdeaPad S540-13API 
  serial: <filter> Chassis: type: 10 v: Lenovo IdeaPad S540-13API serial: <filter> 
  Mobo: LENOVO model: LNVNB161216 v: SDK0J40688WIN serial: <filter> UEFI: LENOVO 
  v: CXCN30WW date: 01/12/2021 
Battery:
  ID-1: BAT0 charge: 14.0 Wh condition: 47.5/56.0 Wh (85%) volts: 10.9/11.5 
  model: SMP L19M3PD3 type: Li-poly serial: <filter> status: Discharging cycles: 189 
CPU:
  Topology: Quad Core model: AMD Ryzen 5 3550H with Radeon Vega Mobile Gfx bits: 64 
  type: MT MCP arch: Zen+ family: 17 (23) model-id: 18 (24) stepping: 1 
  microcode: 8108102 L2 cache: 2048 KiB 
  flags: avx avx2 lm nx pae sse sse2 sse3 sse4_1 sse4_2 sse4a ssse3 svm 
  bogomips: 33538 
  Speed: 1303 MHz min/max: 1400/2100 MHz boost: enabled Core speeds (MHz): 1: 1275 
  2: 1281 3: 1251 4: 1346 5: 1270 6: 1303 7: 1267 8: 1264 
  Vulnerabilities: Type: itlb_multihit status: Not affected 
  Type: l1tf status: Not affected 
  Type: mds status: Not affected 
  Type: meltdown status: Not affected 
  Type: spec_store_bypass 
  mitigation: Speculative Store Bypass disabled via prctl and seccomp 
  Type: spectre_v1 
  mitigation: usercopy/swapgs barriers and __user pointer sanitization 
  Type: spectre_v2 
  mitigation: Full AMD retpoline, IBPB: conditional, STIBP: disabled, RSB filling 
  Type: srbds status: Not affected 
  Type: tsx_async_abort status: Not affected 
Graphics:
  Device-1: AMD Picasso vendor: Lenovo driver: amdgpu v: kernel bus ID: 03:00.0 
  chip ID: 1002:15d8 
  Display: x11 server: X.Org 1.20.10 driver: amdgpu,ati 
  unloaded: fbdev,modesetting,vesa compositor: kwin_x11 resolution: 2560x1600~60Hz 
  OpenGL: renderer: AMD Radeon Vega 8 Graphics (RAVEN DRM 3.40.0 5.10.0-5mx-amd64 
  LLVM 11.0.1) 
  v: 4.6 Mesa 20.3.4 direct render: Yes 
Audio:
  Device-1: AMD Raven/Raven2/Fenghuang HDMI/DP Audio vendor: Lenovo 
  driver: snd_hda_intel v: kernel bus ID: 03:00.1 chip ID: 1002:15de 
  Device-2: AMD Raven/Raven2/FireFlight/Renoir Audio Processor vendor: Lenovo 
  driver: N/A bus ID: 03:00.5 chip ID: 1022:15e2 
  Device-3: AMD Family 17h HD Audio vendor: Lenovo driver: snd_hda_intel v: kernel 
  bus ID: 03:00.6 chip ID: 1022:15e3 
  Sound Server: ALSA v: k5.10.0-5mx-amd64 
Network:
  Device-1: Qualcomm Atheros QCA6174 802.11ac Wireless Network Adapter 
  vendor: Lenovo driver: ath10k_pci v: kernel bus ID: 01:00.0 chip ID: 168c:003e 
  IF: wlan0 state: up mac: <filter> 
  Device-2: Qualcomm Atheros type: USB driver: btusb bus ID: 3-1:2 
  chip ID: 0cf3:e300 
Drives:
  Local Storage: total: 476.94 GiB used: 9.66 GiB (2.0%) 
  ID-1: /dev/nvme0n1 vendor: Samsung model: MZVLB512HBJQ-000L2 size: 476.94 GiB 
  block size: physical: 512 B logical: 512 B speed: 31.6 Gb/s lanes: 4 
  serial: <filter> rev: 3L1QEXF7 scheme: GPT 
Partition:
  ID-1: / raw size: 19.53 GiB size: 19.10 GiB (97.79%) used: 7.57 GiB (39.7%) 
  fs: ext4 dev: /dev/nvme0n1p5 
  ID-2: /home raw size: 61.40 GiB size: 60.19 GiB (98.02%) used: 2.03 GiB (3.4%) 
  fs: ext4 dev: /dev/nvme0n1p7 
  ID-3: swap-1 size: 16.0 MiB used: 0 KiB (0.0%) fs: swap 
  swappiness: 15 (default 60) cache pressure: 100 (default) dev: /dev/nvme0n1p2 
Sensors:
  System Temperatures: cpu: 47.9 C mobo: N/A gpu: amdgpu temp: 47 C 
  Fan Speeds (RPM): N/A 
Repos:
  No active apt repos in: /etc/apt/sources.list 
  Active apt repos in: /etc/apt/sources.list.d/debian-stable-updates.list 
  1: deb http://deb.debian.org/debian buster-updates main contrib non-free
  Active apt repos in: /etc/apt/sources.list.d/debian.list 
  1: deb http://deb.debian.org/debian buster main contrib non-free
  2: deb http://deb.debian.org/debian-security buster/updates main contrib non-free
  Active apt repos in: /etc/apt/sources.list.d/google-chrome.list 
  1: deb [arch=amd64] http://dl.google.com/linux/chrome/deb/ stable main
  Active apt repos in: /etc/apt/sources.list.d/mx.list 
  1: deb http://mirrors.rit.edu/mxlinux/mx-packages/mx/repo/ buster main non-free
  2: deb http://mirrors.rit.edu/mxlinux/mx-packages/mx/repo/ buster ahs
  No active apt repos in: /etc/apt/sources.list.d/various.list 
Info:
  Processes: 305 Uptime: 2m Memory: 14.59 GiB used: 1.95 GiB (13.4%) Init: SysVinit 
  v: 2.93 runlevel: 5 default: 5 Compilers: gcc: 8.3.0 alt: 8 Shell: quick-system-in 
  running in: quick-system-in inxi: 3.0.36 

[JayM]

If you downloaded the MX-KDE ISO file rather than getting it via bittorrent, did you verify its integrity against the md5/sha512 checksum files before burning it to a USB stick or other bootable media?

If you boot from the live USB do you have the same issue?

What did you use to burn the ISO file with?

FYI there's a newer BIOS/UEFI version than the one you have that may (or may not) fix the problem: https://pcsupport.lenovo.com/us/en/prod ... IOS%2FUEFI. From its README file:

CXCN31WW:
BIOS Notification :
1. Fixed
1) Fix the issue that the panel at the last order brightness don't turn off the backlight completely.

so it does seem to address display backlight issues.